MainMarketDocumentation
Get Access
Get started
  • Welcome
  • Getting started
  • Authentication
  • Pricing
Concepts
  • Stores, chains, products
  • Pricing tiers + freshness
  • Indices + methodology
  • Coupons
Use cases
  • Cheapest near me
  • Track price trends
  • Resolve a shopping list
  • Compare across chains
  • Coupons & deals nearby
  • Plan an in-store route
  • Monthly inflation snapshot
Reference
  • API Reference →
  • Methodology
  • OpenAPI spec
  • Agent skill spec
Get started
  • Welcome
  • Getting started
  • Authentication
  • Pricing
Concepts
  • Stores, chains, products
  • Pricing tiers + freshness
  • Indices + methodology
  • Coupons
Use cases
  • Cheapest near me
  • Track price trends
  • Resolve a shopping list
  • Compare across chains
  • Coupons & deals nearby
  • Plan an in-store route
  • Monthly inflation snapshot
Reference
  • API Reference →
  • Methodology
  • OpenAPI spec
  • Agent skill spec

Pricing

$0.01 per data call. Free discovery.

MainMarket is pay-per-call. Discovery endpoints (the catalog of stores and chains, the OpenAPI spec, the methodology doc) are free so an agent can shop the API without spending anything. Data endpoints (prices, products, coupons, indices, aisles, list resolution) are $0.01 USDC per request.

ℹ
No subscription, no minimum
There's no monthly fee, no signup, and no minimum spend. Fund a wallet with $0.10 and you have ten paid calls. See Getting started for the AgentCash flow.

Free routes

These return data without any Authorization header. Use them to discover what stores and chains exist before issuing paid calls.

MethodPathPurpose
GET/v1/storesGeo-search stores
GET/v1/stores/{id}Single store detail
GET/v1/chainsBulk chain lookup
GET/v1/chains/{slug}Single chain detail
GET/healthLiveness + DB ping
GET/openapi.jsonFull OpenAPI 3.1 spec
GET/skill.mdAgent-facing skill manifest
GET/llms.txtLLM crawler manifest
GET/prompts.jsonPrebuilt agent prompts
GET/.well-known/x402x402 discovery
GET/.well-known/mppMPP discovery
GET/methodology.mdIndex methodology doc

Paid routes — $0.01 each

Each call to one of these endpoints requires an x402 / MPP payment proof, an internal Cart token, or a B2B API key. See Authentication for the full flow.

MethodPathPurpose
GET/v1/productsCatalog search
GET/v1/products/{id}/couponsCoupons for one product
GET/v1/pricesStore-level prices, tiered fallback
GET/v1/couponsActive coupons + geo filter
GET/v1/coupons/{id}All deals for one coupon
GET/v1/coupons/{id}/savingsSavings computation
GET/v1/stores/{id}/couponsCoupons available at one store
GET/v1/stores/{id}/aislesAisles for one store
GET/v1/chains/{slug}/aislesAisles aggregated per chain
POST/v1/chains/{slug}/resolve-listBulk shopping-list resolver
GET/v1/indices/{slug}Monthly published index series

Settlement rails

  • Base USDC (x402) — primary rail. Settles in ~1 second per call. USDC contract 0x8335...02913. Network: eip155:8453.
  • Tempo USDC (MPP) — secondary rail. Currently a stub; the 402 challenge advertises both protocols, but verification falls through to x402 until pympp ships a full verifier.

Volume and enterprise

For dashboards, recurring agents, or anything north of a few thousand calls per month, an enterprise B2B key avoids per-call settlement latency and gives you a single monthly invoice. SLAs on freshness and additional chain coverage are negotiable.

Contact hello@mainmarket.com with your volume, the routes you intend to hit, and any chain or geo coverage requirements.